Electronic mail (e-mail) has rapidly become one of the most widely used application on the Internet and one of the most popular means of communication today, both for business purposes and for personal enjoyment. It is a quick and efficient way of maintaining regular contact and communicating on a worldwide scale. Statistics show that over 30 million people will use e-mail within any given twenty-four hour period.
E-mail may be understood to be essentially “the transmission of messages over communications networks”. An e-mail message is an electronic letter, which is transmitted via the Internet. To enable parties to communicate on the same terms when sending and receiving e-mail messages, devices on the network use a standard form of communication, known as a protocol. SMTP (Simple Mail Transfer Protocol) is the standard Internet protocol used in communications between the client and server and “forms the backbone of the Internet mail system”. The protocol that allows for files of various types—for example, video or graphic files—to be sent and received by e-mail, is known as MIME (Multipurpose Internet Mail Extensions).
Once an e-mail message has been composed and sent, it is typically relayed to an SMTP server. A server is basically a computer, providing a service to other computers on the same network. A client is essentially a computer that requests a service from a computer functioning as a server.
An SMTP server typically communicates through and understands only SMTP. The SMTP server checks the e-mail address of the recipient and relays the mail to the recipient's mail server. When the message arrives at the recipient's mail server, the message is stored in the recipient's mailbox on the SMTP server until it is retrieved by the recipient.
Mailbox formats are many and varied. A popular mailbox format is ‘mbox’, which is used by SENDMAIL®. SENDMAIL® is a Mail Transfer Agent, which is a program that moves mail from one machine to another. SENDMAIL® implements a general internet work mail routing facility, featuring aliasing and forwarding, automatic routing to network gateways, and flexible configuration. The ‘mbox’ mailbox format works by storing all messages together in one single file. All stored messages include the ‘from’ line of the e-mail message, in order to define where each new message starts. An alternative mailbox technology, particularly for use with QMAIL® is called ‘Maildir’. With ‘Maildir’, the mailbox has a directory and subdirectories. Rather than storing all messages together in one file, a new file is created for each message and all messages are stored separately.
E-mail notification systems allow recipients to define their own notification criteria, content and destination. For example, a recipient could request to be notified only when messages arrive from a certain email address and for the notification to contain only the subject line of the message. The notification could be sent to the recipient's pager, via an e-mail gateway, notifying the recipient that there is mail waiting in the recipient's mailbox.
One example of a Notification System is USA.Net's ‘Electronic Message Forwarding System’, U.S. Pat. No. 5,937,161. This system works by relaying messages from one address to a second address, based on a recipient's previously defined criteria. Incoming messages are queued while the recipient's previously defined filter criteria are checked. The message is subsequently retrieved from the queue and the filter criteria are applied thereto. If the criteria are satisfied, a notification is then composed and transmitted.